Researchers have roundly condemned Facebook’s experiment in which it manipulated nearly 700,000 users’ news feeds to see whether it would affect their emotions, saying it breaches ethical guidelines for “informed consent”. James Grimmelmann, professor of law at the University of Maryland, points in an extensive blog post that “Facebook didn’t give users informed consent” to allow them to decide whether to take part in the study, under US human subjects research. “The study harmed participants,” because it changed their mood, Grimmelmann comments, adding “This is bad, even for Facebook.” But one of the researchers, Adam Kramer, posted a lengthy defence on Facebook, saying it was carried out “because we care about the emotional impact of Facebook and the people that use our product.”